<div id="viewport-locked" style="position:relative;height:400px;width:400px;background: var(--neutral-layer-4);overflow:auto">
    <FluentAnchoredRegion Anchor="anchor-locked" Viewport="viewport-locked"
                          VerticalPositioningMode="AxisPositioningMode.Locktodefault"
                          VerticalDefaultPosition="VerticalPosition.Bottom"
                          HorizontalPositioningMode="AxisPositioningMode.Locktodefault"
                          HorizontalDefaultPosition="HorizontalPosition.Right">
        <div style="height:150px;width:150px;background:var(--neutral-layer-2);" />
    </FluentAnchoredRegion>
    <div style="position:relative;height:0;width:0">
        <FluentAnchoredRegion Anchor="anchor-locked" Viewport="viewport-locked"
                              VerticalPositioningMode="AxisPositioningMode.Locktodefault"
                              VerticalDefaultPosition="VerticalPosition.Top"
                              HorizontalPositioningMode="AxisPositioningMode.Locktodefault"
                              HorizontalDefaultPosition="HorizontalPosition.Right">
            <div style="height:100px;width:100px;background:var(--highlight-bg);" />
        </FluentAnchoredRegion>
    </div>
    <FluentAnchoredRegion Anchor="anchor-locked" Viewport="viewport-locked"
                          VerticalPositioningMode="AxisPositioningMode.Locktodefault"
                          VerticalDefaultPosition="VerticalPosition.Top"
                          HorizontalPositioningMode="AxisPositioningMode.Locktodefault"
                          HorizontalDefaultPosition="HorizontalPosition.Left">
        <div style="height:50px;width:50px;background:var(--accent-fill-active);" />
    </FluentAnchoredRegion>
    <div />
    <FluentButton Appearance=Appearance.Neutral id="anchor-locked" style="margin-left:100px;margin-top:150px">anchor</FluentButton>
</div>
